In recent years, light-weight flexible electronic components, sensors, or wirings have been necessary and indispensable to satisfy size or weight reduction or efficiency enhancement of electronic devices, energy devices, or the like. It is known to perform pattern application of a conductive paste onto a printed wiring board or flexible printed board to form a circuit or electrode and thereby form a flexible circuit wiring. As the paste, known is a conductive paste containing (A) a metal such as Ag (silver), Au (gold), Cu (copper), Al (aluminum), Ni (nickel), Pt (platinum), or Pd (palladium), (B) a resin having one or more groups selected from the group consisting of an epoxy group, an oxetane group, a 3,4-epoxycyclohexyl group, and from 5 to 8-membered cyclic ether groups and reactive with a carboxyl group, and (C) a curing agent reactive with the above-described resin (refer to Patent Document 1).
A circuit or electrode formed using such a conductive paste, however, poses problems such as decomposition of the resin or oxidation of a metal lacking in heat resistance, for example, under high temperature conditions of from about 300° C. to 400° C.
Metal oxide materials are on the other hand characterized in that they are stable to an oxidation reaction even at high temperatures and they are more inexpensive than noble metals so that they can be used widely as a resistor material. However, electronic parts such as resistors have conventionally been manufactured by screen printing an inorganic material paste obtained by mixing a conductive material, a glass frit, a vehicle, and an appropriate organic solvent to a base material made of an inorganic material such as alumina and then drying and firing the resulting base material. It is therefore difficult to manufacture them on a flexible board such as polyethylene terephthalate (PET) because it usually includes a high-temperature firing procedure (refer to Patent Documents 2 to 4).